I'm trying to decode this AES string: https://cryptopals.com/static/challenge-data/7.txt (from here)
The page simply says it's been AES encrypted in ECB mode using the key YELLOW SUBMARINE
.
The Crypto-JS library should be able to decode this. The docs show a simple method, and I'm using it like so:
// message is the base64 data in the link above
// key is: YELLOW SUBMARINE
const decrypted = CryptoJS.AES.decrypt(message, key, {
mode: CryptoJS.mode.ECB
});
return decrypted.toString(CryptoJS.enc.Utf8);
Except then it throws an error on the last line: "Malformed UTF-8 data". I've tried a number of different things including all the different paddings and trying to convert the base64 data to either hex or utf-8 first. It's always that same error.
I'm really at a loss of what I'm doing wrong here.
Here's a stupid simple jsfiddle: https://jsfiddle.net/jg7hwLuk/
CodePudding user response:
The key must be passed to decrypt()
as WordArray
. This can be achieved with the Utf8 encoder.
The ciphertext can be passed directly as Base64 encoded string and is implicitly converted to a CipherParams
object by CryptoJS.
This allows the ciphertext to be decrypted:
var message = "CRIwqt4 szDbqkNY I0qbDe3LQz0wiw0SuxBQtAM5TDdMbjCMD/venUDW9BLPEXODbk6a48oMbAY6DDZsuLbc0uR9cp9hQ0QQGATyyCESq2NSsvhx5zKlLtzdsnfK5ED5srKjK7Fz4Q38/ttd stL/9WnDzlJvAo7WBsjI5YJc2gmAYayNfmCW2lhZE/ZLG0CBD2aPw0W417QYb4cAIOW92jYRiJ4PTsBBHDe8o4JwqaUac6rqdi833kbyAOV/Y2RMbN0oDb9Rq8uRHvbrqQJaJieaswEtMkgUt3P5Ttgeh7J hE6TR0uHot8WzHyAKNbUWHoi/5zcRCUipvVOYLoBZXlNu4qnwoCZRSBgvCwTdz3Cbsp/P2wXB8tiz6l9rL2bLhBt13Qxyhhu0H0 JKj6soSeX5ZD1Rpilp9ncR1tHW8 uurQKyXN4xKeGjaKLOejr2xDIw aWF7GszU4qJhXBnXTIUUNUfRlwEpS6FZcsMzemQF30ezSJHfpW7DVHzwiLyeiTJRKoVUwo43PXupnJXDmUysCa2nQz/iEwyor6kPekLv1csm1Pa2LZmbA9Ujzz8zb/gFXtQqBAN4zA8/wt0VfoOsEZwcsaLOWUPtF/Ry3VhlKwXE7gGH/bbShAIKQqMqqUkEucZ3HPHAVp7ZCn3Ox6 c5QJ3Uv8V7L7SprofPFN6F kfDM4zAc59do5twgDoClCbxxG0L19TBGHiYP3CygeY1HLMrX6KqypJfFJW5O9wNIF0qfOC2lWFgwayOwq41xdFSCW0/EBSc7cJw3N06WThrW5LimAOt5L9c7Ik4YIxu0K9JZwAxfcU4ShYu6euYmWLP98 qvRnIrXkePugS9TSOJOHzKUoOcb1/KYd9NZFHEcp58Df6rXFiz9DSq80rR5Kfs M Vuq5Z6zY98/SP0A6URIr9NFu Cs9/gf q4TRwsOzRMjMQzJL8f7TXPEHH2 qEcpDKz/5pE0cvrgHr63XKu4XbzLCOBz0DoFAw3vkuxGwJq4Cpxkt eCtxSKUzNtXMn/mbPqPl4NZNJ8yzMqTFSODS4bYTBaN/uQYcOAF3NBYFd5x9TzIAoW6ai13a8h/s9i5FlVRJDe2cetQhArrIVBquF0L0mUXMWNPFKkaQEBsxpMCYh7pp7YlyCNode12k5jY1/lc8jQLQJ EJHdCdM5t3emRzkPgND4a7ONhoIkUUS2R1oEV1toDj9iDzGVFwOvWyt4GzA9XdxT333JU/n8m N6hs23MBcZ086kp9rJGVxZ5f80jRz3ZcjU6zWjR9ucRyjbsuVn1t4EJEm6A7KaHm13m0vwN/O4KYTiiY3aO3siayjNrrNBpn1OeLv9UUneLSCdxcUqjRvOrdA5NYv25Hb4wkFCIhC/Y2ze/kNyis6FrXtStcjKC1w9Kg8O25VXB1Fmpu 4nzpbNdJ9LXahF7wjOPXN6dixVKpzwTYjEFDSMaMhaTOTCaqJig97624wv79URbCgsyzwaC7YXRtbTstbFuEFBee3uW7B3xXw72mymM2BS2uPQ5NIwmacbhta8aCRQEGqIZ078YrrOlZIjar3lbTCo5o6nbbDq9bvilirWG/SgWINuc3pWl5CscRcgQQNp7oLBgrSkQkv9AjZYcvisnr89TxjoxBO0Y93jgp4T14LnVwWQVx3l3d6S1wlscidVeaM24E/JtS8k9XAvgSoKCjyiqsawBMzScXCIRCk6nqX8ZaJU3rZ0LeOMTUw6MC4dC aY9SrCvNQub19mBdtJUwOBOqGdfd5IoqQkaL6DfOkmpnsCs5PuLbGZBVhah5L87IY7r6TB1V7KboXH8PZIYc1zlemMZGU0o7 etxZWHgpdeX6JbJIs3ilAzYqw/Hz65no7eUxcDg1aOaxemuPqnYRGhW6PvjZbwAtfQPlofhB0jTHt5bRlzF17rn9q/6wzlc1ssp2xmeFzXoxffpELABV6 yj3gfQ/bxIB9NWjdZK08RX9rjm9CcBlRQeTZrD67SYQWqRpT5t7zcVDnx1s7ZffLBWm/vXLfPzMaQYEJ4EfoduSutjshXvR VQRPs2TWcF7OsaE4csedKUGFuo9DYfFIHFDNg 1PyrlWJ0J/X0PduAuCZ uQSsM/ex/vfXp6Z39ngq4exUXoPtAIqafrDMd8SuAtyEZhyY9V9Lp2qNQDbl6JI39bDz 6pDmjJ2jlnpMCezRK89cG11IqiUWvIPxHjoiT1guH1uk4sQ2Pc1J4zjJNsZgoJDcPBbfss4kAqUJvQyFbzWshhtVeAv3dmgwUENIhNK/erjpgw2BIRayzYw001jAIF5c7rYg38o6x3YdAtU3d3QpuwG5xDfODxzfL3yEKQr48C/KqxI87uGwyg6H5gc2AcLU9JYt5QoDFoC7PFxcE3RVqc7/Um9Js9X9UyriEjftWt86/tEyG7F9tWGxGNEZo3MOydwX/7jtwoxQE5ybFjWndqLp8DV3naLQsh/Fz8JnTYHvOR72vuiw/x5D5PFuXV0aSVvmw5Wnb09q/BowS14WzoHH6ekaWbh78xlypn/L/M nIIEX1Ol3TaVOqIxvXZ2sjm86xRz0EdoHFfupSekdBULCqptxpFpBshZFvauUH8Ez7wA7wjL65GVlZ0f74U7MJVu9SwsZdgsLmnsQvr5n2ojNNBEv qKG2wpUYTmWRaRc5EClUNfhzh8iDdHIsl6edOewORRrNiBay1NCzlfz1cj6VlYYQUM9bDEyqrwO400XQNpoFOxo4fxUdd AHmCBhHbyCR81/C6LQTG2JQBvjykG4pmoqnYPxDyeiCEG JFHmP1IL jggdjWhLWQatslrWxuESEl3PEsrAkMF7gt0dBLgnWsc1cmzntG1rlXVi/Hs2TAU3RxEmMSWDFubSivLWSqZj/XfGWwVpP6fsnsfxpY3d3h/fTxDu7U8GddaFRQhJ 0ZOdx6nRJUW3u6xnhH3mYVRk88EMtpEpKrSIWfXphgDUPZ0f4agRzehkn9vtzCmNjFnQb0/shnqTh4Mo/8oommbsBTUKPYS7/1oQCi12QABjJDt LyUan 4iwvCi0k0IUIHvk21381vC0ixYDZxzY64 xx/RNID iplgzq9PDZgjc8L7jMg 2 mrxPS56e71m5E2zufZ4d nFjIg dHD/ShNPzVpXizRVUERztLuak8Asah3/yvwOrH1mKEMMGC1/6qfvZUgFLJH5V0Ep0n2K/Fbs0VljENIN8cjkCKdG8aBnefEhITdV7CVjXcivQ6efkbOQCfkfcwWpaBFC8tD/zebXFE JshW16D4EWXMnSm/9HcGwHvtlAj04rwrZ5tRvAgf1IR83kqqiTvqfENcj7ddCFwtNZrQK7EJhgB5Tr1tBFcb9InPRtS3KYteYHl3HWR9t8E2YGE8IGrS1sQibxaK/C0kKbqIrKpnpwtoOLsZPNbPw6K2jpko9NeZAx7PYFmamR4D50KtzgELQcaEsi5aCztMg7fp1mK6ijyMKIRKwNKIYHagRRVLNgQLg/WTKzGVbWwq6kQaQyArwQCUXo4uRtyzGMaKbTG4dns1OFB1g7NCiPb6s1lv0/lHFAF6HwoYV/FPSL/pirxyDSBb/FRRA3PIfmvGfMUGFVWlyS7 O73l5oIJHxuaJrR4EenzAu4Avpa5d VuiYbM10aLaVegVPvFn4pCP4U/Nbbw4OTCFX2HKmWEiVBB0O3J9xwXWpxN1Vr5CDi75FqNhxYCjgSJzWOUD34Y1dAfcj57VINmQVEWyc8Tch8vg9MnHGCOfOjRqp0VGyAS15AVD2QS1V6fhRimJSVyT6QuGb8tKRsl2N a2Xze36vgMhw7XK7zh//jC2H";
var key = "YELLOW SUBMARINE";
const decrypted = CryptoJS.AES.decrypt(message, CryptoJS.enc.Utf8.parse(key), {
mode: CryptoJS.mode.ECB
});
document.getElementById("pt").innerHTML = decrypted.toString(CryptoJS.enc.Utf8);
<script src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/4.0.0/crypto-js.min.js"></script>
<p style="font-family:'Courier New', monospace;" id="pt"></p>
<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>